In my co-pending patent application, Ser. No. 36,874, filed May 7, 1979, I have disclosed the use of stacked vehicular tires as generally toroidal heat collection elements of a solar heating system which included a thermal energy storage medium such as a rock bed or water tank in the center of the stack. I have found that there is a need to provide a mechanism for more efficient heat transfer between the tires and either the thermal energy storage medium or a living space to be heated. I have discovered that by coupling together these generally toroidal elements with suitably located conduits, it is possible to define an air or fluid path in heat exchange relationship with these elements which passes angularly through the hollow interior of each element and serially through these elements. It is then possible to set up a recirculating air or fluid path including this path through the interiors of the toroidal elements for transferring the solar radiant energy absorbed by these elements to either the thermal energy storage medium at the center of the stack or to a living space to be heated.